scholarly journals CLOSED N=2 STRINGS: PICTURE-CHANGING, HIDDEN SYMMETRIES AND SDG HIERARCHY

2000 ◽  
Vol 15 (26) ◽  
pp. 4191-4236 ◽  
Author(s):  
OLAF LECHTENFELD ◽  
ALEXANDER D. POPOV
Keyword(s):  
Effective Field Theory ◽  
Dimensional Space ◽  
Effective Field ◽  
Spectral Flow ◽  
Hidden Symmetries ◽  
Commuting Flows ◽  
Brst Cohomology ◽  
Gravity Equations ◽  
Dimensional Space Time ◽  
Infinite Set

We study the action of picture-changing and spectral flow operators on a ground ring of ghost number zero operators in the chiral BRST cohomology of the closed N=2 string and describe an infinite set of symmetry charges acting on physical states. The transformations of physical string states are compared with symmetries of self-dual gravity which is the effective field theory of the closed N=2 string. We derive all infinitesimal symmetries of the self-dual gravity equations in (2+2)-dimensional space–time and introduce an infinite hierarchy of commuting flows on the moduli space of self-dual metrics. The dependence on moduli parameters can be recovered by solving the equations of the SDG hierarchy associated with an infinite set of Abelian symmetries generated recursively from translations. These nonlocal Abelian symmetries are shown to coincide with the hidden Abelian string symmetries responsible for the vanishing of most scattering amplitudes. Therefore, N=2 string theory "predicts" not only self-dual gravity but also the SDG hierarchy.

scholarly journals HIDDEN SYMMETRIES OF THE OPEN N=2 STRING

2001 ◽  
Vol 16 (02) ◽  
pp. 303-329
Author(s):  
TATIANA A. IVANOVA ◽  
OLAF LECHTENFELD
Keyword(s):  
Effective Field Theory ◽  
Moduli Space ◽  
Dimensional Space ◽  
Effective Field ◽  
Integrable Hierarchy ◽  
Hidden Symmetries ◽  
Yang Mills ◽  
Dimensional Space Time ◽  
Infinite Set ◽  
Twistor Description

It is known for ten years that self-dual Yang–Mills theory is the effective field theory of the open N=2 string in (2+2)-dimensional space–time. We uncover an infinite set of Abelian rigid string symmetries, corresponding to the symmetries and integrable hierarchy of the self-dual Yang–Mills equations. The twistor description of the latter naturally connects with the BRST approach to string quantization, providing an interpretation of the picture phenomenon in terms of the moduli space of string backgrounds.

scholarly journals SOME ALGEBRAIC SYMMETRIES OF (2, 2)-SUPERSYMMETRIC SYSTEMS

2001 ◽  
Vol 16 (10) ◽  
pp. 663-671
Author(s):  
TRISTAN HÜBSCH
Keyword(s):  
Field Theory ◽  
Effective Field Theory ◽  
Hilbert Spaces ◽  
Dimensional Space ◽  
Space Time ◽  
Effective Field ◽  
Target Space ◽  
Two Dimensional ◽  
Target Field ◽  
Dimensional Space Time

The Hilbert spaces of supersymmetric systems admit symmetries which are often related to the topology and geometry of the (target) field-space. Here, we study certain (2, 2)-supersymmetric systems in two-dimensional space–time which are closely related to superstring models. They all turn out to possess some hitherto unexploited and geometrically and topologically unobstructed symmetries, providing new tools for studying the topology and geometry of superstring target space–times, and so the dynamics of the effective field theory in these.

scholarly journals Cosmological Cutting Rules

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Scott Melville ◽  
Enrico Pajer
Keyword(s):  
Effective Field Theory ◽  
Effective Field ◽  
Field Theories ◽  
Tree Level ◽  
Optical Theorem ◽  
Loop Order ◽  
Founding Principle ◽  
Lower Loop ◽  
Infinite Set ◽  
The Universe

Abstract Primordial perturbations in our universe are believed to have a quantum origin, and can be described by the wavefunction of the universe (or equivalently, cosmological correlators). It follows that these observables must carry the imprint of the founding principle of quantum mechanics: unitary time evolution. Indeed, it was recently discovered that unitarity implies an infinite set of relations among tree-level wavefunction coefficients, dubbed the Cosmological Optical Theorem. Here, we show that unitarity leads to a systematic set of “Cosmological Cutting Rules” which constrain wavefunction coefficients for any number of fields and to any loop order. These rules fix the discontinuity of an n-loop diagram in terms of lower-loop diagrams and the discontinuity of tree-level diagrams in terms of tree-level diagrams with fewer external fields. Our results apply with remarkable generality, namely for arbitrary interactions of fields of any mass and any spin with a Bunch-Davies vacuum around a very general class of FLRW spacetimes. As an application, we show how one-loop corrections in the Effective Field Theory of inflation are fixed by tree-level calculations and discuss related perturbative unitarity bounds. These findings greatly extend the potential of using unitarity to bootstrap cosmological observables and to restrict the space of consistent effective field theories on curved spacetimes.

scholarly journals HIDDEN SYMMETRIES IN QUANTUM FIELD THEORIES FROM EXTENDED COMPLEX NUMBERS

1999 ◽  
Vol 14 (26) ◽  
pp. 4201-4235 ◽  
Author(s):  
PASCAL BASEILHAC
Keyword(s):  
Field Theory ◽  
Dimensional Space ◽  
Field Theories ◽  
Complex Numbers ◽  
Quantum Field Theories ◽  
Quantum Field ◽  
Hidden Symmetries ◽  
Dimensional Space Time ◽  
Extended Complex ◽  
Dual Models

The two-dimensional space–time sine–Gordon field theory is extended algebraically within the n-dimensional space of extended complex numbers. This field theory is constructed in terms of an adapted extension of standard vertex operators. A whole set of nonlocal conserved charges is constructed and studied in this framework. Thereby, an algebraic nonperturbative description is possible for this n-1 parameters family of quantum field theories. Known results are obtained for specific values of the parameters, especially in relation to affine Toda field theories. Different (dual)-models can then be described in this formalism.

Topology knots and hierarchy problem

2019 ◽  
Author(s):  
Vitaly Kuyukov
Keyword(s):  
Quantum Theory ◽  
String Theory ◽  
Quantum Gravity ◽  
Dimensional Space ◽  
Space Time ◽  
Elementary Particles ◽  
Hierarchy Problem ◽  
Topological Quantum ◽  
Dimensional Space Time ◽  
New Formula

Many approaches to quantum gravity consider the revision of the space-time geometry and the structure of elementary particles. One of the main candidates is string theory. It is possible that this theory will be able to describe the problem of hierarchy, provided that there is an appropriate Calabi-Yau geometry. In this paper we will proceed from the traditional view on the structure of elementary particles in the usual four-dimensional space-time. The only condition is that quarks and leptons should have a common emerging structure. When a new formula for the mass of the hierarchy is obtained, this structure arises from topological quantum theory and a suitable choice of dimensional units.

Effective Field Theory in Particle Physics and Cosmology

2020 ◽  
Keyword(s):  
Field Theory ◽  
Effective Field Theory ◽  
Particle Physics ◽  
Large Scale ◽  
Effective Field ◽  
Effective Theory ◽  
Soft Collinear Effective Theory ◽  
Multiple Length Scales ◽  
Cosmological Observations ◽  
Standard Models

Effective field theory (EFT) is a general method for describing quantum systems with multiple-length scales in a tractable fashion. It allows us to perform precise calculations in established models (such as the standard models of particle physics and cosmology), as well as to concisely parametrize possible effects from physics beyond the standard models. EFTs have become key tools in the theoretical analysis of particle physics experiments and cosmological observations, despite being absent from many textbooks. This volume aims to provide a comprehensive introduction to many of the EFTs in use today, and covers topics that include large-scale structure, WIMPs, dark matter, heavy quark effective theory, flavour physics, soft-collinear effective theory, and more.

The Fujita-Miyazawa force in the light of effective field theory

2008 ◽  
Author(s):  
Ulf-G. Meiβner ◽  
Hideyuki Sakai ◽  
Kimiko Sekiguchi ◽  
Benjamin F. Gibson
Keyword(s):  
Field Theory ◽  
Effective Field Theory ◽  
Effective Field
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